Explosion engine and method of operating the same



April 8 1924.

' H. F. SHEPHERD EXPLOSION ENGINE AND METHOD OF OPERATING THE SAME 2Sheets-Sheet 1 Filed Nov. 19, 1919 A ril 8 1924.

H.F. SHEPHERD EXPLOSIO N ENGINE AND METHOD OF OPERATING THE SAMESheets$heet Fil ed Nov. 19 1919 W//////I////l/llll I (June mic: M /V54954 atto'mam Patented Apr. 8, 1924.

UNITED stares EPAEEttTYQFFNE.

HAROLD F. SHEPHERD, OF GROVE CITY. PENNSYLVANIA. ASSIGNOR TO THE BESSIE-MER GAS ENGINE COMPANY. OF GROVE CITY. PENNSYLVANIA, A CORPORATION OFPENNSYLVANIA.

EXPLOSION ENGINE AND METHOD or OPERATING THE Application filed NovemberTo all whom it may concern:

Be it known that I. IIAROLD F. SHEPHERD, a citizen of the United States,residing at Grove City, in the county of Mercer and State'ot'Pennsylvania, have invented new and useful Improvements in ExplosionEngines and Methods of )perating the Same,

. of which the following is a specification.

In the operation of two cycle engines difficulty is experienced inobtaining a wide range of efficient performance. If the introduction ofscavenging air is such as to eilect good results where the engine isrunning under heavy load this same introduc- 16 tion of air for lightloads will so reduce the temperature in the combustion chamber as tomake it difficult to operate. This is particularly true Where theignition is accomplished througha hot plate which receives 20 its heatfrom the explosions, which heat is utilized for igniting the succeedingcharges. 'ith the scavenging charge as hereinbefore introduced forefiicient running at heavy load the mean temperature ofthe combustionchamber when running at a very light load falls below the ignitiontemperature.

Consequently it is impossible to maintain ahot plate at theignitiontemperature from theheat of the explosion alone and if anattempt is made to continue the operation of the engine running lightfor any length of time-theengine will stall. On the other hand if theintroduction of scavenging air as heretofore introduced is controlled soas to properly take care of the light loads there is a great falling ottin efficiency at the heavy loads.- Heretofore the quantity of scavengingcharge has been varied and the velocity of the air as it is introducedhas been varied somewhat but the. manner of introduction has not beensuch as to accomplish a correction of the difliculty above described. i

- I have discovered that where the scaveng ing air is introduced as itcommonly is through a port against a deflector plate on the piston, thusdirecting the scavenging charge toward the opposite end of the cylinderfrom which it sweeps around to the exhaust port if the velocity of thisscavenging charge is materially increased it mixes to a greaterextentwith the burnt gases of the previous explosion through the for-19, 1919. Serial No. 339,090.

nration'of more pronounced eddies in the chamber and in consequence thepropor duced is increased. On the other hand, when.

the engine is running at full load it is desirable to have thescavenging air introdueed more slowly. In this instance less eddies areformed and there is a gradual displacement of the burnt gases so thatthere is a more complete scavenglng. action.

Under these conditions there is enough heat developed to maintain aproper combustion in the chamber.

The results are better attained where the quantity of scavenging air ismaintained approximately constant regardless of the velocity. Incarrying out my invention, therefore, I vary the manner of theintroduction of the scavenging air so as to increase. the proportionateheat from an explosion inversely as the force of the explosion varies.In this way I am able to maintain an even running of the-engine atverylight loads and for any period'desired and when the engine is subjectedto heavy load I obtain the maximum efiiciency incident to a completescavenging by a slow introduction of scavenging air.. y

This method may be conveniently carried out by merely varying theclearance of the scavengingpump By increasing the clearance the pressureof the compressed air is varied without materially changing the quantityof-air that is pumped.

In the accompanying drawings I have shown a mechanism for carrying outmy method and an exeinplification of the mecha-' nism forming myinvention as follows Fig. 1 shows a side elevation of the engine, thecylinder and immediately adjacent parts being'in section.

- Fig; 2is a section on the line 22 in Fig. 1.

Fig. 3 a sectional view showingan alternative construction of theclearance shift-- ing device.

v 1 marks the engine frame, 2 the cylinder which'extends from the frame,3 the piston in the cylinder, 4 the piston rod, and'5 the exhaust port9,these ordinarily bei'ngoppoular cooling system or chambers 17 of thesitelyplaced in the cylinder and the piston is provided with adeflecting surface 10.- This operates in a well-known-manner deflecting,the incoming scavenging air toward .the rear of the cylinder from whichit sweeps around to the exhaust port 9 carry ing thie greater portion ofthe burnt gases with it.

Fuel :is delivered through a fuel injector 11 of any approved type andthe hot plate 12 forms the bottom of a receptacle13 material 14, such assulphur is provided in the receptacle 13. The receptacle is closed by acondenser plate 15 which is cooled from water in the chamber 16, thechamber 16 being connected with the regcylinder head 17 This hot plateis heated by the explosions and the temperature of the hot plate is keptconstant at the vaporizing point of the substance retained in thereceptacle by reason of the fact that as soon as the substance vaporizesthe vapor dissipates the heat and is condensed by the condensingsurface, returning to the liquid substance after such condensation. Bythis means the hot plate is kept at the ignition temperature which isdesired. The scavenging air is drawn in through the inlet18, passing theinlet check valve 19. A chamber is arranged around. the end of thecylinder and forms'a re ceiver for the air drawn in by the pistonthrough the valve 19 and compressed as the piston moves forward. Thechamber 20 is connected by a passage 21 with the inlet port 8.

The chamber or receiver 20 isof such size relatively to the.displacement of the piston to give to the scavenging air a pressurewhich when delivered through the inlet port as this port is uncovered bythe piston is higher than is desirable for the highest economy, that isto say, the velocity is so great that eddies are formed in.the cyl inderand more or less of the incoming air is mixed with the burnt gases sothat -a higher temperature is maintained with this I high velocity thanis desirable where the engine is running under heavy load but; gives amean temperature WlllCll' 1s suflicient to maintain the hot/plate atignition temperature." Consequently the engine can idle with thedelivery of air so arranged.

In order to provide for greater economy that will arise from a slowerintroduction a of air when the engine is workingheavily I provide asupplemental chamber which in- 47 is mounted on a shaft '48:

creases the clearance between the piston and the inlet port andconsequently reduces the pressure at which air is introduced. A plate 22is secured to the side of the chamber 20 and a clearance controllingdevice 23 is secured-to this plate. A passage 24 extends from thechamber 20 through the plate 22 and into the bodyof the device 23. Thispassage extends through a valved opening 25 and by way of a passage .26and opening 27 to a supplemental chamber 28 arranged below the chamber20. A valve 29 controls the opening25. Itis provided with a stem 30which extends upwardly and is secured to a piston 31. The piston 31operates in a cylinder 32. ,A small passage 33 connects the passage 24with the upper end of the cylinder 32; A valve 34 controls the passage33. The valve 34 is provided with a stem 35' and a spring 36, maintainsthe valve normally in'closed position. The

stem is provided with'a button 37 at its upper end in position to arm ofarock lever 38. The'rock lever is pivotally mounted at 39 on an arm 40exbe engaged by an tending from the body of the device 23. :A

link. 41 connects the rock lever 38 with a rock lever 42. The rockleveris pivoted at 42 on an arm 42 extending from the governor frame 50. Onearm of the rock lever is connected to a sliding spool 43 con nected bylinks .44 with the governor weights 46 from a cross head 47 The shaft 48is journaled in the bearing 49 and stepped on the hearing by means of acollar" 51.

The weights 45 are carried by links.

The cross head- A bevelled gear 52 is fixed on the shaft 48 and engagesa. bevelled gear 53. The f bevelled gear 53is fixed on a shaft 54, theshaft 54 being mounted in bearings 55. A pulley 56 is mounted on theshaft 54. A belt 57 extends from the pulley 56 to the pulley 58 on'theengine shaft. It will be readily seen that as the engine speeds upwardly the rock arm 38 through the linkage shown'and described is'rocked so as to open the valve 34 thus opening, communication betweenthe upper end of the cylinder by way of tliepassage 33 with the passage24, under which circumstances the pressure both sides of the piston 31is balanced. The valve 29 under-these circumstances is closed by aspring 29 and the scavenging air then is, confined to the chamber-2.0and enters the cylinderwith avelocity which has heretoffore beendescribed. It will be understood and thefgovernor weights arecarriedoutthat for, affewstrokes of the engine air 9 will be delivered past thevalve 29, the valve 29 acting as a check until the chamber. 28 is filledto the higher pressure.

When, however, .thezengine slows down under load the governor balls dropand this movement is communicated through the linkage described so as tomove the rock arm 38 out of engagement with the button 37, .thuspermitting the closing of the valve 34. Under these circumstances thevalve 34 acts as a check and air is pumped into thecylinder 32 until thepressure above the pis:

ton reaches the maximum pressure. At the same time the pressure underthe valve 29is the maximum pressure andconsequently the area of thevalve 29 should be less than the- 'PlStOIl 31 so that when the pressurein the chamber or on the underside of the piston 31 is at its lowest thepreponderance of pressure above thepiston is sufficient to overcome thepressure belo'w the valve 29 supplemented by the springj29and thus openthe valve '29. The air above the piston remains'trapped by the. valve 34and any 1eakage,'of course,

.'is taken 'care of with each pulsation of the pump so that the valve 29s maintained in its open position. This opening of the valve takes placein a very few strokes. During the time the valve 29 is open theclearance space includes not only the chamber 20 but the chamber 28 asbefore-described.

It will be noted, however,th'at notwithstanding'this greater clearanceand smaller compressionithe amount of scavenging air which is introducedwill remain approximately constant and'conseq'uently there will be aslarge a volume under the conditions of less velocity as with the highervelocity. There will he therefore, a better scavenging and a moreefiicient operation of the engine under heavy load because with aslowintroduction of air the incoming air does notso' intimately interminglewith the burnt gases and therefore there is alower mean temperature inthe explosion chamber than would be the case if the scavenging were lessperfect.-

In Fig. 3 there is shown'an alternative construction of a clearancecontrolling de-' vice in which a manually controlled valve 59.

is substituted for the valve 29. The valve 5 9 is a rotary valve and hasa way which can be brought into register with the way or passage 24giving an easy bend into the passage 26. The valve issupplied with apulley 61 to which maybe attached a cord b means of which the valve maybe operate from'a distance.

What I claim as new is 1 1. In an explosion engine, the combination of acombustion chamber; means for iiitroducing and igniting fuel to effect atwo cycle operation; means for introducing equal quantities ofscavengingairwith-each'explosion; and means for varying the velocity of the air asit is introduced inversely asthe force of the explosion varies.

2. In an explosion engine, the combination of a combustion chamber;means for introducing and igniting fuel to effect a two 7 e py leoperation; apump synchronized with varying the clearance of the pump tovary the pressure of-the air compressed. and its velocity on itsintroduction to the combustion chamber, said clearance being increasedas the force of the explosion isincreased.

3. In an explosion engine, the combination of a combustion chamber; apiston operating' in the chamber; means for introducing and ignitingfuel to effect a two cycle operation; a pump in which the piston acts asthe displacing element; means for conveying air from the air pump to thecombustion chamher; and means for increasing the clearance of the pumpasthe force-of the explosion increases. r

4. In an explosion engine',the combination of a combustion chamber;means for introducing and ignitingfuel'to efiect a two cycle operation;a pump synchronized with said engine compressing scavengingair; meansfor conve 'ng the air compressed to the combustion c amber';and-automatic means for varying the clearance of the pump to vary thepressure of the air compressed and itsvelocity on its introduction tothe combustion chamber, said clearance being increased as the force ofthe explosion is increased.

5. In an explosion engine, thecombination' of a combustion chamber; apistonoperating 'in the chamber; means for'introducing and ber;andautomatic means for increasing the clearance of the pump as the forceof the explosion increases. ,I

6. In an explosion engine, the combination of a combustion chamber; ahotp'late subjected to the heat of the explosions for igniting thecharges in said-chamber means for introducing equal quantities ofscavenging air with each explosion; and means for varying the velocityof the'air as it is introduced inversely as the force of the explosionvaries. i

7. In -an explosion engine, the combina-.

tion of a combustion chamber; a hot plate.

for maintaining said hot plate at a constant temperature; means forintroducing equal quantities of scavenging air with each explosion; andmeans for varyingthe mansubjected to theheat ofthe explosions forigniting the charges in said chamber; means ner of introductienof theair to va the propor'tionate'i'ieat retained from an explosion inverselyas the force of the explosion varies.

8. In an explosion engine, the comblna-.

tion of a combustion chamber; 'a hotplate subjected to the heat of theexplosions for igniting the chaiges in said chamber; means formaintaining said hot plate at a constant temperature; means forintroducing equal ity of the air auxiliary means for conveying the airfrom the pump to the combustion chamber; and automatic" quantities ofscavenging air with each explosion; and means for varying the velocasthe force of the explosion varies.

9. In an explosion engine, the combination ofa combustion chamber; meansfor introducing and igniting fuel to eiiect a 'two cycle operation; apump synchronized with said engine compressing scavenging air; anclearance chamber for said pump;

means for connecting and'disconnecting the auxiliary clearance chamberfrom the pump, said means connecting the auxiliary clearance chamberwith the pump as the force ofthe explosion decreases. v

10. In an expldsion engine, the combination of a combustion chamber; ahot plate subjected to the-heat of the explosions for ignitingthecharges m said chamber; a .pump synchronized withlsaid enginecompressing a scavenging air; an auxiliary clearance chamber for saidpump; means for conveying the air from-the pump to the combustionchamber; and automatic means a for connecting anddisconnecting theauxiliary clearance chamber from the pump, said means connecting theauxiliary clearance I chamber with the pump as the force of the i thepump .to the' combustion chamber; andas theforce of the ex losionincreases.

' use mixture.

explosion increases.

11. In an explosion engine, the combination'of ,a combustionchamber;'a-hot plate subjectedto the heat of the explosions for ignitingthechai'ges in said chamber; means for maintaining said ,hot plate-at aconstant temperature;- a pump synchronized with said engine compressinga scavenging air; an auxiliary clearance chamber for said pump meansautomatic-means for connecting and "disconnecting the auxiliaryclearance. chamber from the pump, said means connecting the auxiliaryclearance chamber with the pump '12. The method 0' operating two cycleexplosive engines which consists in exploding a mixture; introducing ascavenging air; varying the manner ofintroducing the air and varying itsadmixture with the burnt gases and thus varying the proportionate heatretained from the explosion inversely as the force of theexplosionvaries; and introducing a fuel toform anexplosive 18. The method ofoperating two cycle explosive engines ing a mixture; .ntroducing ascavenging air; varying the manner of introducing the air and varyingits admixture with the burnt gases and thus varyingthe proportionateheat retained from the explosion in verselyas the, forveoi the explosionvaries;

as it is introduced inversely for conveying the air from which consistsin explodintroducing a fuel to form an explosive mixture; and varyingthe fuel introduced to vary the forcebf the explosion.

14'. The method of operating two cycle explosive engines'wliich consistsin. exploding a mixture; introducing equal quantities of scavenging air;varying the manner of introducing such air to vary its admixture withthe b'unntf gases to vary the -pi'opor' tion'atef he'at-retained from anexplosion inversely as the force of the explosion varies; andintroducing a fuel-to form an ex plosiv'e mixture:

15. The method-of operating two cycle explosive engines "which consistsin. exploding a mixture; introducing a scavenging air; directing the airand varying its velocity'to vary its admixture with the burnt gases tovary the proportionate heat retained from an'explosion inversely as theforce of the explosion" varies; and introducing fuel ltd form anexplosive mixture.

explosive engines which"cons ists in explodvarying the proportionateheat retained a from the explosion inversely as the force of the exploson. varies; and introducing a fuel to form an, explosive mixture.

which consists in exploding a mixture by heat generated in precedingexplosions; in-

troducing equal quantities of scavenging air;

varying the manner of introducing'su'ch air to' vary its admixture withthe burnt gases to:vary

the proportionate heat r:

18. The method. oitsoperating two 'cycle' explosive engines igniting themixturefrom I llO tained from an explosion inversely as the "force ofthe explosion varies; and introducing a fuel to form an explosivemixture. 19. The method of operating two cycle explosive engines whichconsists in exploding a mixture by igniting the mixture from heatgenerated in preceding explosions; introducair; varying the velocitying-a scavenging I of the air as introduced inversely as the 'force' ofthe ex losion varies; and varying iits admixture with the'iburnt gasesand thus varying the proportionate heat retained from an explosion and,introducing fuel to form an explosive mixture.

20. The method-ofoperating two cycle exs plosive engines which consistsin exploding a mixture by igniting the mixture from heat generated inprecedin explosions; introducmg equal quantities 0 scavenging air;varying the velocity of the air as introduced inversely as the forceofthe explosion varies; and introducing fuel to form an explosive mixture.21. The method of operating twocycle explosive engines .which consistsin exploding a mixture; compressing scavenging air with impulsescorresponding to the explosions and introducing said scavenging air witheach compression toa point of explosion; varying t e' manner ofintroducing the air and varying its admixture with the burnt gases andthus varying the proportionate heat retained from the explosioninversely as the force of the explosion varies; and

introducing a fuel to form an explosive mixture.

22. The method of operating two cycle ex plosive engines which consistsin exploding a mixture; compressing scavenging air with impulsescorresponding to the explosions plosiveengines which consists inexploding a mixture; compressing scavenging air wlth a constantdisplacement and introducing the same; varying the manner of introducingthe air to vary its admixture with the burnt gases to vary theproportionate heat retained from the explosion inversely -.as the forceof the explosion varies; and introducing a fuel to form an explosivemixture.

24. The method of operating two cycle explosive engines which consistsinexploding a mixture; compre'ss'ng scavenging air with a constantdisplacement and introducing the same; varying the velocity of the airas introduced inversely as the force of the explosion varies; andintroducing fuel to form an explosive mixture.

25. The method of operating two cycle explosive engines which consistsin exploding a mixture; compressing scavenging air with impulsescorresponding to the explosions "and with a constant displacement and introducing the same; varylng'the manner of introdudng the air to vary itsadmixture with the burnt gases to vary the proportionate heat retainedfrom the explosions inversely as the force of the explosions vary; andintroducing a fuel to form an explosive mixture. v

In testimony whereof I have hereunto set my hand.

HAROLD F. SHEPHERD.

